Layer structure, plasma jet, and thermal dynamics of Cu target irradiated by relativistic pulsed electron beam

Abstract

This paper, based on a relativistic electron-beam accelerator with inductive energy accumulation, investigates the layer structure, plasma jet, and thermal dynamics of Cu target under the irradiation of pulsed electron beam (350 kV, 4 kA, 300 ns). A description of a relativistic electron beam source with a carbon fiber cathode is presented. After the electron-beam irradiation at 13 J/cm 2 energy density, microcraters with 0.5-1 mm diameter appeared on the target surface, and the target cross section is characterized by multilayer structures with a 20 mm thickness melting layer and a cellular layer. Further, it was found that the carbon content increased significantly not only on the target surface but also on the cross section. The gas liberation per pulse induced by electron beam is analyzed. A good agreement between the experimental and calculated perveances was observed, with the exception at the end of the accelerating pulse possibly due to the participation of ion flow from the anode target. In the pulsed emission, there existed material transfer from anode to cathode, which is observed by the identification of elemental compositions on cathode surface. As the beam energy is deposited on target surface, the anode plasma jet is generated, and expands toward the cathode at a velocity of 3 cm/ms. By solving the one-dimensional heat equation, 10 9 K/s heating rate and 10 7 K/m temperature gradient can be obtained. After the heating of pulsed electron beam, the thermal conduction is dominant, with a cooling rate on the order of 10 7 K/s. The relativistic electron beam sources may provide a potential development for target experiments and high energy density physics.

Simultaneous operation of X band gigawatt level high power microwaves

“…There are numerous applications of HPMs in material processing, plasma heating, and environment improving (Barker et al, 2001;Thumm & Kasperak, 2002;Hong et al, 2009), among others. In recent years, benefiting from the rapid development of pulse power technologies Kovalchuk et al, 2009;Mao et al, 2009;Cheng et al, 2009), electron emitter technologies (Li et al, 2009b(Li et al, , 2009c, and so on Aria et al, 2009), HPM sources generating narrow-band HPMs (Korovin et al, 2003) have been developed extensively. Efforts have also been made on increasing the output power, pulse duration, and conversion efficiency of these devices.…”

Ion jet generation in the ultraintense laser interactions with rear-side concave target

“…The advent of ultrashort ultraintense laser pulses led to the development of new exciting fields in laser plasma interaction (Karsch et al, 1999;Malka et al, 2004;Roth et al, 2005;Mangles et al, 2006;Kawata et al, 2005;Yu et al, 2005;Glowacz et al, 2006;Koyama et al, 2006;Lifshitz et al, 2006;Sakai et al, 2006;Yu et al, 2007;Hora, 2007;Dromey et al, 2009;Fazio et al, 2009;Hoffmann 2008aHoffmann , 2008bKasperczuk et al, 2009aKasperczuk et al, , 2009bLaska et al, 2007;Limpouch et al, 2008;Malekynia et al, 2009;Sharma & Sharma 2009;Izgorodin et al, 2009;Li et al, 2009;Sadighi-Bonabi et al, 2009;Hong et al, 2009;Kline et al, 2009). The generation of energetic ion beams from laser plasma interaction is an exciting area of research with important applications ranging from medical proton therapy (Bulanov & Khoroshkov, 2002), high-energydensity physics (Patel et al, 2003), to fast ignition in inertial confinement fusion .…”